Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended			12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020		Sep. 30, 2019	Dec. 31, 2019
Cash flows from operating activities:
Net loss	$ (27,894)	$ 6,349	$ (25,201)		$ (5,789)
Adjustments to reconcile to net cash provided by operating activities:
Depreciation and amortization			26,853		26,530
Gain on sale of fixed assets			(568)		(527)
Equity-based compensation expense			8,081		5,981
Deferred income taxes			(1,670)		883
Non-cash restructuring charges			1,067		6,419
Goodwill impairment	39,430	0	40,688	[1],[2]	0
Definite-lived intangible asset impairment	0	0	957		0
Impairment of assets held for sale			0		11,946
Gain on sale of businesses			(109)		0
Loss on foreign currency transactions			420		370
Other			767		(39)
Changes in operating assets and liabilities (net of acquisitions):
Receivables net, retainage and contract assets			16,135		(1,488)
Inventories			6,283		(3,170)
Prepaid expenses and other assets			(4,953)		2,225
Accounts payable and accrued expenses			3,198		(8,476)
Contract liabilities			(381)		(1,435)
Other operating			7,812		(1,779)
Net cash provided by operating activities			79,379		31,651
Cash flows from investing activities:
Capital expenditures			(15,238)		(21,392)
Proceeds from sale of fixed assets			1,143		1,270
Patent expenditures			(264)		(292)
Sale of businesses, net of cash disposed			3,602		0
Net cash used in investing activities			(10,757)		(20,414)
Cash flows from financing activities:
Proceeds from issuance of common stock upon stock option exercises			0		956
Repurchase of common stock			(5,251)		(28,143)
Distributions to non-controlling interests			(153)		(1,409)
Credit facility amendment fees			(1,995)		0
Payments on notes payable, net			0		(273)
Proceeds from (payments on) line of credit, net			(24,000)		8,000
Principal payments on long-term debt			(26,250)		(19,688)
Net cash used in financing activities			(57,649)		(40,557)
Effect of exchange rate changes on cash			(451)		(970)
Net increase (decrease) in cash, cash equivalents and restricted cash for the period			10,522		(30,290)
Cash, cash equivalents and restricted cash, beginning of year			66,222		84,886	$ 84,886
Cash, cash equivalents and restricted cash, end of period	$ 76,744	$ 54,596	$ 76,744		$ 54,596	$ 66,222

[1] During the second quarter of 2020, the Company recorded a $1.3 million goodwill impairment related to restructuring activities within Energy Services (see Note 4).

[2] During the third quarter of 2020, the Company recorded a $39.4 million goodwill impairment within Energy Services (see Note 2).